• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.114-120
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• 1997

Microorganisms producing xylanase were screened for the enzymatic production of xylo-oligo saccharides from xylan. One of the bacteria isolated from compost produced an endoxylanase extracellularly. The bacterium was identified as Bacillus sp. according to its taxonomic characteristics examined. Xylanase production reached upto 5 U/ml after 22 h of culture in LB medium at $30^{\circ}C$. The xylanase was purified by ammonium sulfate precipitation and gel filtration. The molecular weight of the xylanase was estimated to be 20,400 by SDS-PAGE. Optimal temperature and pH for the xylanase activity was $60^{\circ}C$ and 6.5, respectively. The enzyme was stable at temperatures upto $40^{\circ}C$ and pH values from 4 to 10. The xylanase was completely inhibited by the addition of 2 mM mercury ion. Apparent $K_m$ and $V_max$ values for oat spelt xylan were 9.2 mg/ml and 1954 U/mg protein, respectively. For birchwood xylan, the values were 6.3 mg/ml and 1009 U/mg protein. The predominant products of the xylan hydrolysis were xylobiose, xylotriose and xylotetraose, indicating that the enzyme is an endoxylanase. Upto $85{\%}$ of the initially added enzyme (2 U/ml) was bound to 50 mg/ml of the insoluble fraction of oat spelt xylan after incubation at $30^{\circ}C$ for 30 min.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.50-58
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• 1996

Interspecific hybrids between Aspergillus oryzae var oryzae and A. nidulans 514 were obtained by nuclear transfer technique. Several autotrophic mutants isolated from conidiospores of the two strains were mutagenized with ultraviolet and N-methyl-N-nitrosoguanidine. Optimal conditions for formation of intergeneric hybrids were investigated. Frequencies of hybrid formation by nuclear transfer were $3{\times}10^{-5}{\sim}1{\times}10^{-5}$. From observation of genetic stability, conidial size, DNA content, and nuclear stain, it was suggested that their karyptypes are aneuploid. The hybrids showed 1.1~1.4 fold higher xylanase activities than parental strains did. The xylanase of Aspergiilus sp. TAVD514-3 was purified and some of it's enzymatc characteristics were investigated. The enzyme was purified about 85 fold with an overall yield of 17% from the culture medium by ammonium sulfate fractionation, Sephadex G-75 gel permeation chromatography, and CM-sephadex A-50 ion exchange chromatography. The purified enzyme functions optimally at pH 9.0 and 80$^{\circ}C$. The enzymatic activity was increased by the presence of $Mg^{2+}$ and $Mn^2$ ions.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.526-531
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• 1988

Procedure for the purification of pretense from culture broth of Streptomyces sp. SMF301 was developed. It was evident that the strain produced two different proteases of which molecular weights were estimated to be 23, 500 and 38, 900 dalton. It was found that the optimum pH of the smaller was 9.0 and that of the larger was 1.0. The optimal temperature of the alkaline pretense was 5$0^{\circ}C$ and that of the neutral pretense was much more stable than neutral protease at extreme condition viz. high temperature, and pH.

• Herbal Formula Science
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• v.17 no.2
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• pp.163-174
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• 2009

Reactive oxygen species(ROS) can induce hepatotoxicity and trigger apoptosis in the liver. In this study, we investigated the sulfated polysaccharide A-1 from Opuntia ficus-indica against alcoholic oxidative stress in human liver Hep G2 cell. An antioxidant substance A-1 obtained from the enzymatic extract of Opuntia ficus-indica fruit was purified by DEAE-cellulose ion exchange and sephadex G-100 gel permeation chromatography. The purification yield and molecular weight were 14.3% and 1.8 KDa, respectively. The A-1 predominately contained arabinose, galactose, rhamnose and also sulfate group. The structure of A-1 was investigated by periodate oxidation, FT-IR spectroscopy, $^1H$-NMR spectroscopy. The A-1 mainly composed of alternating unit of ${\rightarrow}4$)-$\alpha$-L- Rapp-2-$SO_3^-$-$\alpha$-L-Galp-($1{\rightarrow}$ and branched linkage of $\beta$-D-Arbp- ($5{\rightarrow}$. The antioxidative activity was measured using the SOD, CAT activity and GSH assay, respectively. The expression of Nrf2 protein was analyzed by western blotting. The viable cell count analyzed by autofluorescence. Oxidative stress induced by ethanol(1 M) were dramatically reduced by A-1 treatment. A-1 also prevented cell death induced by oxidative stress. It also increased expression Nrf2 protein level. We concluded that sulfated polysaccharide A-1 from Opuntia ficus-indica effectively protect Hep G2 liver cell from alcoholic oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.5
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• pp.434-442
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• 1990

Aspergillus sp. CC-29 ws selected for its strong protease activity among various stains of molds found in soil. It was found that the production of alkaline protease reached to maximum when the wheat bran medium containing glucose as carbon source had been cultured for 4 days. Alkaline proteased was purified 36.10 fold from Aspergillus sp. CC-29 The purification procedures included ammonium sulfate fractunation gel filteration on Sepha-dex G-75 G-150 and DEAE-cellulose ion-exchange chromatography, The yield of the purified enzyme was 22.40% The purified enzyme was confirmed as a single band by the polyacryla-mide. When the purified enzyme was applied to SDS-PAGE the molecular weight was estima-ted 24000. The optimum pH for the enzyme activity was 9.0 and the optimum temperature was 4$0^{\circ}C$ The reaction of this enzyme followed typical Michaelis-Menten kinetics with the Km value of 2.10$\times$10-4M with the Vmax of 29.41 $\mu$g/min. The enzyme was reactively stable in alkalic condition and unstable by heat treatment. The activity of alkaline protease was increased by the addition of Ca2+ whereas it was inhibited by Hg2+ Zn2+ at concentration of 1$\times$10-3M.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.355-361
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• 2007

Cotyledons of perilla6 were cultured on MS medium containing 0.5 mg/l NAA and 0.5 mg/l BA for 7 weeks. The activity of perilla peroxidase was observed to increase following culture stages as assessed by peroxidase assay. A peroxidase (POD) was purified from perilla tissue cultured on MS medium for 7 weeks. The peroxidase was purified using ion exchange and gel nitration chromatography. The perilla peroxidase had a molecular mass of 30 kDa by SDS-PAGE. We showed that the N-terminal amino acid sequence of this protein shared 67% identity with the tea peroxidase. As indicated by SDS-PAGE, the banding pattern of the 30 kDa polypeptide present in total soluble protein from perilla tissue was increased following culture stages. Immunoblot analysis indicated that perilla peroxidase protein appeared after 3 weeks of perilla tissue culture, and continued to increase with extended duration of tissue culture for at least 7 weeks.

• Korean Journal Plant Pathology
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• v.12 no.1
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• pp.99-108
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• 1996

3종의 빙핵세균 Peudomonas syringae 8401, Pseudomonas fuorescens 8701, Erwinia herbicola 8701의 세포 외막으로부터 아무런 변성제도 사용치 않고 sucrose density gradient centrifugation, Sephacryl gel filtration chromatography, DEAE-cellulose ion exchange chromatography, non-denaturing buffer를 이용한 PAGE, electroelution, SDS-PAGE를 통해 빙핵활성 단백질을 고도로 정제할 수 있었다. P. suringae와 P. fluorescens에서는 각각 3종류(155 kD, 75 kD, 50 kD)의 빙핵활성 단백질이, E. herbicola에서는 155 kD를 제외한 2종류(75 kD, 50 kD)의 빙핵활성 단백질은 이 연구를 통해 처음 밝혀진 것으로 , 지금까지 보고된 빙핵활성 단백질(150 KD 이상)보다는 훨씬 작은 것이다. 이는 빙핵활성을 나타내는 단백질의 기본단위는 이 실험의 결과만에 의하면 최대 50 kD임을 시사한다. 이들 단백질은 그 유래된 세균의 종류나 또는 단백질 분자량의 크기에 관계없이 모두 -5.5~7.5$^{\circ}C$에서 물을 동결시키는 높은 빙핵활성을 갖고 있었다. 이는 지금까지 보고된 어느 정제단백질의 빙핵활성보다 높은 것이다. 정제된 단백질의 빙핵활성은 trypsin 처리에 의해 상실되었고, pH6~8범위에서는 안정하였으며, pH5이하, pH9이상에서는 활성을 상실하였다. 보존온도에 대한 영향은 3$0^{\circ}C$이상이 되면 점차 활성이 감소하는 경향을 보이다 37$^{\circ}C$이상에서는 활성이 완전히 상실되었다. 금속이온으로서 Hg\ulcorner이온과 SDS에 의해 활성이 상실되었으나 phosphatidylinositol의 첨가에 의해서는 활성이 약간 증가(-1$^{\circ}C$)하였다.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.456-460
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• 1993

The present study was conducted to investigate Angiotensin I-converting enzyme(ACE) inhibition activity of the components of traditional tea materials in Korea. Angiotensin I-converting enzyme(ACE) inhibition activity of water soluble fractions obtained from the samples were strong in Zingiberis rhizoma, Acantopanacis cortex, Schizandrae fructus, Perilla semen, Cassiae torae semen, Zizyphy fructus in order. ACE inhibition activity of fractions obtained from methanol extract of Cassiae torae semen were strong in ethyl acetate fraction, ethyl ether fraction, water fraction, chloroform fraction in order. Compound C showed the strongest ACE inhibition activity among compound A, B, C, D separated from Cassiae torae semen, but Compound C separated from Cassiae torae semen was lower than bradykinin in the ACE inhibition activity.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.157-163
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• 2009

This study was conducted for the isolation, purification, and characterization of a protease from Korean pear, to see its proteolytic activity on chicken actomyosin and to find the optimum pH and temperature of activity on chicken actomyosin. The protease was isolated from crude extract of Korean pear by ammonium sulfate precipitation. Further purification was done by DEAE-Sepharose ion-exchange chromatography, Mono-Q and Mini-Q column chromatography. The purified enzyme gave a single protein band on SDS polyacrylamide gel electrophoresis and the molecular weight was found to be 38 kDa. The specific activity of purified enzyme was 34,907 unit/mg with 25 fold purification and the yield was 2%. The purified enzyme incubated with chicken actomyosin showed high activity. The optimum pH and temperature for enzyme activity on chicken actomyosin were 6.5 and $70^{\circ}C$, respectively. A protease was purified from Korean pear for the first time and characterized. It was found to be promising for meat tenderization.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.285-289
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• 2007

A 3% suspension of heat-stabilized defatted rice bran was treated with papain, followed by inactivating the enzyme by heat, and centrifuged. The supernatant was subjected to ultrafiltration, and fractions with various molecular sizes, F1 (>30 kDa), F2 (10-30 kDa), F3 (5-10 kDa), F4 (3-5 kDa), and F5 (3 kDa<), were freeze-dried, and evaluated for antimutagenicity by Ames test using Salmonella typhimurium TA 100 against phenazine methosulfate. The F3 fraction containing highest antimutagenicity from ultrafiltration was separated into 6 fractions by DEAE-Sephadex A-25 ion-exchange column chromatography (F3-1-F3-6). Each fractions having protein contents were pooled, dialyzed, freeze dried, and evaluated for antimutagenicity. Among the six fractions, the F3-1, F3-2, and F3-6 fractions showed antimutagenicity, which were 80.2, 53.4, and 58.6% at concentration of $100\;{\mu}g/plate$, respectively. These F3-1, F3-2, and F3-6 fractions were subjected to Sephadex G-50 gel filtration column chromatography for further purification. Among the purified fractions, the F3-1-1, F3-2-2, and F3-6-1 fractions showed antimutagenicity of 84.5, 58.6, and 69.8% at concentration of $100\;{\mu}g/plate$, respectively. It is thought that these peptides can find application for nutraceutical and pharmaceutical products.